What stroke burns the most calories

The doc wanted to see me this week in order to refill a medication prescription. Just after 8 holiday parties, I went in and was weighed as usual. Oh boy. I know I gain during the winter and loose it in the more active summer, but did I need to be weighed right after Christmas? My weight increased so that now for the first time in my life I am considered overweight (but no obese:D), according to the BMI calculation. I have begun watching calories & keeping track of calories in a written log, (which I understand is good for achieving results.) As part of my 'recovery', I am also discovering how to burn calories. So how many calories does each stroke burn? From the internet, in a one hour swim (assume that means swimming continuously) for my weight / age: ..backstroke 651 ..breaststroke 931 ..butterfly 1024 ..freestyle fast 931 ..freestyle moderate 651 (Note to self: 1 pound of body fat = 3500 calories)